Echo Problem X100P vs TDM cards


#1

I currently have 4 x100p cards in an Asterisk@home system I’ve built. The system runs fine with external voip connections. When I route calls thru the x100p clones I get echo problems and popping noises. I have been searching and found that this is a common problem with these cards. I’m considering switch to TDM cards because I’ve haven’t seen anyone complaining about echo issues.

I was wondering if someone could verify that the TDM does not have the same echo problems as the X100P.

Thanks for you help.


#2

The TDM cards handle echo better than the X100Ps but you still need to deal with it…


#3

save yourself headache and get FXO with real hardware canceller DSP


#4

suggestions would be useful !!

cgaspard, i think a lot depends on your locale and the properties of the telco line you’re connected to.

i’ve done sites with TDM cards and they’ve been fine. but only when a few things have been followed through … get the card onto its own IRQ and into a PCI 2.2 slot. google for imcompatibilities with your mainboard/box. make sure you have the CPU horsepower. ensure wctdm is loading with the settings for your locale. get the gains in zapata.conf set right. there’s more, but the wiki at voip-info.org (search for echo and tdm) will give you the info you need.

don’t rely solely on other peoples settings. i recently installed an Asterisk box for an existing user as a hot spare. same everything except the TDM card. gain settings were different to avoid echo !!

[quietly]i’m going to be trying some Sangoma A200 cards next week too !![/quietly]


#5

the pickings for FXO with decent hardware cancellers seems pretty thin.

Mediatrix 1204
Cisco

there are probably others. quintum maybe?

basically you want to look for something with a G.168 canceller with better than 8ms tail. they wont be cheap though.